The loadouts of the FIA characters contain the Radio_R148.et which is the same radio as USSR characters have. This radio has set "coldBorscht" as radio encryption key. But the default FIA faction config says that the radio encryption key for this faction is "beefGulash". That leads to the bevahior that no FIA player can use his own radio but USSR players can use the FIA radios. If I change the radio encryption key of the radio to "beefGulash" then the FIA player can use it. Alternatively, when I set the radio encryption key of the FIA faction to "" an empty string then they can use all radios of all factions.

Please create a new variant of that radio, for example Radio_R148_FIA.et and change the encryption key to "beefGulash" and then replace the radio in all characters.